In IBISWorld, you will find a report for the Unmanned Aerial Vehicle (UAV) Manufacturing industry in the US. ProcurementIQ also includes a report for buyers of UAVs.

Also, try Marketresearch.com Academic.

• Search for drone. There are several reports.

Search Business Source Complete.

• Search for trade, academic, and news articles using keywords such as: drones OR uav OR unmanned aerial vehicles.

Also, see resources such as the FAA's Unmanned Aircraft Systems page, AUVSI (Association for Unmanned Vehicle Systems International) and UA.